Abstract The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.

RACIONAL: O correto posicionamento da sonda nasogástrica para nutrição enteral tem sido alvo de várias investigações, demonstrando as controvérsias e a complexidade do procedimento. OBJETIVO: Prever as medidas antropométricas para realizar a inserção de sonda para nutrição enteral até o estômago empregando a esofagogastroduodenoscopia para calcular-se o comprimento necessário até o estômago. MÉTODO: Medidas externas foram obtidas entre a ponta do nariz vs lobo da orelha vs apêndice xifóide vs umbigo e altura correlacionadas com a medida padrão obtida em pacientes submetidos à esofagogastroduodenoscopia diagnóstica. RESULTADOS: Encontrou-se correlação estatisticamente significativa entre a transição esofagogástrica identificada durante a endoscopia, acrescida da distância da rima labial à arcada dentária superior, com a distância compreendida entre os pontos anatômicos lóbulo da orelha e apêndice xifóide (r=0.75). CONCLUSÃO: A distância entre o lóbulo da orelha ao apêndice xifóide (0.75) e a distância entre o lóbulo da orelha ao apêndice xifóide até o ponto médio da cicatriz umbilical, subtraindo a distância da ponta do nariz ao lóbulo da orelha, foram parâmetros anatômicos seguros para estimar-se a distância da transição esofagogástrica. A altura na posição em pé (r = 0,72) também pode ser utilizada como um indicador da distância necessária para inserir o tubo no estômago.

BACKGROUND:The correct placement of a nasogastric tube for enteral nutrition is subject of several investigations, demonstrating the controversy of the procedure. AIM: To establish an external measure that can correspond to the internal measurement which determines the insertion length of nasogastric feeding tube up to the stomach. METHODS: External measures were obtained between points: nose tip vs earlobe vs xiphoid appendix vs umbilicus and height correlated with the standard measures obtained from patients undergoing diagnostic esophagogastroduodenoscopy. RESULTS: It was found a significative statistical correlation between esophagogastric junction, identified during the esophagogastroduodenoscopy, with the distance measured between the anatomic points of the earlobe and xiphoid appendix (r= 0.75) and from this line with the orthostatic height (r=0.72). CONCLUSION: The distance between the earlobe to the xiphoid appendix (0.75) and the distance between the earlobe to the xiphoid appendix to the midpoint of the umbilicus, subtracting the distance from tip of nose to earlobe, were safe anatomical parameters to reach the esophagogastric junction. The height in the standing position (r= 0.72) also can be used as an indicator of the length necessary to insert the tube into the stomach. The height in the standing position (r= 0.72) also can be used as an indicator of the length necessary to insert the tube into the stomach.

OBJETIVO: Os xenoenxertos são uma alternativa aos enxertos autogênicos e devem ser osteocondutores e biocompatíveis. Um estudo recente demonstrou que as características físicas e químicas das hidroxiapatitas encontradas no comércio não são condizentes com as descrições dos fabricantes. Este estudo avalia a biocompatibilidade e a osteocondução de um xenoenxerto derivado de osso medular bovino. MÉTODOS: Quinze coelhos adultos, pesando entre 2.500g e 3.000g cada um, foram anestesiados e submetidos a procedimentos cirúrgicos para criar três perfurações na tíbia, com 2 mm de diâmetro. Esses orifícios foram preenchidos com coágulo sanguineo, Osseus® e Bio-Oss®. Os animais foram sacrificados depois de 7, 14 e 28 dias. RESULTADOS: A análise histopatológica da interface de osso e biomaterial mostrou ligeira resposta inflamatória depois de 7 dias, que esteve ausente nos períodos subsequentes. Ambos os materiais foram parcialmente substituídos por tecido ósseo diretamente em contato com a superfície dos materiais, sem ocorrência de fibrose. CONCLUSÃO: Concluímos que ambos os materiais são biocompatíveis e absorvíveis, o que permite progressiva aposição óssea na superfície durante todo o período de avaliação.

OBJECTIVE: Xenografts are an alternative to autogenous grafts and must be osteoconductive and biocompatible. A recent study has demonstrated that the physical and chemical characteristics of commercially available hydroxyapatites do not fit the manufacturers' descriptions. This study evaluates the biocompatibility and osteoconduction of a xenograft derived from bovine medullary bone. METHODS: Fifteen adult rabbits weighing between 2,500 g and 3,000 g each were anesthetized and subjected to surgical procedures to create three perforations in the tibia, with a diameter of 2 mm. These were filled with blood clot, Osseus® and Bio-Oss®. The animals were euthanized after 7, 14 and 28 days. RESULTS: Histopathological analysis of the interface between the bone and the biomaterial showed a slight inflammatory response after 7 days, which was absent in the subsequent periods. Both materials were partially replaced by bone tissue directly in contact with the surface of the materials, without the occurrence of fibrosis. CONCLUSION: We concluded that both materials are biocompatible and absorbable, allowing for progressive bone apposition on the surface throughout the evaluation period.